Motor driven razor



Jan. 6, 1942.

' G. R. ERlcsoN ETAL MOTOR DRIVEN RAZOR Filed July 16, 1958 I INVENTORS BYWQM ATTORNEY. I

7 inch; although the Patented Jan. 1942 g 1 UNITEDZTSTATE S PATENT F I E Moron pluvsn Razor. 7. George lt .-Ericson. Kirkwood, ,and'lohn H.- Kinsey, V sumo-.11. H,

Application July 10, 1938, Serial No. 210.634

I This invention relates to motor-driven -rasors and particularly to means forfcontrollingthe direction as the razoris moving, and assume that the cutter bar onlyis oscillating and that the movements of the cutter bar or blade or both.

In the construction of the razor according to my invention! use a rotating or oscillating cutter bar having a surface 'which ispartly cylindrical and in thisicylindrical surface 1 form a multiplicity of recesses which terminate in the cylindrical portion ofthe surface, the ends of the recesses being preferably formed at an acute angle'so as to form something approaching a cutting edge which not only assists in the cut- 7 ting action but tends to provide a clearance for The'blade is preferably ofrspecial construction and may be formed of a strip of hard razorsteel 10 to zo'thousandths of an inch in thickness and from to of an inch in width. The length is comparatively to 1 inches has been found to be convenient The blade is preferably sharpened from one side only in order to give maximum clearance to enable the cutting edge skin. without pressure. The beveled side of the to be brought close to the,

the rest of the whisker to be cut off, thus the razor has to'be passedover the faceseveral ftimes in order to getthe-whiskersdown to the lithe razor is whiskers are. prominently i of an -inch "long.

whenxthe edge of the blade approaches to within less than is of an inch of thebase of the whisker. say for instance within 95,00, the oscillating cutter bends theiwhisker up'against the edge of .the blade-and cuts off the top leaving it M 'of an inch long, the cutter bar passing" over the edge of the blade also tucks the end of the whisker under the blade. and the blade then slides over it. leaving noopportunity to have proper length.

opposite dlrectionithe whiskers are bent over in the direction that the razor is movingand only get a chance to spr u and be cut on after the 'edgegof the blade-has passedover the end of unimportant'but 1 inch the whisker, which meansthat'theedge of the blade must be nearly the'complete length of the whisker away from that point where ;it"ioins the skin; that-is to say the base of theflwhisker.

Obviously in such case the amount of whisker which'is to be cut off at each passage of the blade 'overthe skin depends on the flexibility of blade is for this reason placed outwardly; while I the unbeveled side rests againstthe cutteribar. The razor is held in a holder which is held concentrically with the cutter'bar so as to permit it to'oscillate; the cutter bar is also constructed and arranged to oscillate about the-same axis. The cutter bar and blade holder are mounted on a frame or handle which contains avmotor of conventional construction. The motor is connected to oscillate the cutter liar and blade simultaneously, although the movement of the cutter bar is preferably greater thanthat of the blade. .yThe actual degreexof movement of the blade back andforth is inthe order of i of an movement is small as M o of an inch will give satisfactory The greatthe skin andthe amount of shifting which can be done by the "cutter: bar. 4

From the above description it will be seen that there is a substantial dimculty with razors of this type in which already one cutter bar and blademembers are oscillated, and it will also be understood that thlsldimclilty would exist regardless of which of these members isoscillated. By withdrawing the blade slightly. as the oscillating cutter bar is also withdrawn in'the er movements may be'usedif desired. The cutterbar is preferably in the order of to of an inch,although some variation is permissible.

The purposeof the double oscillating arrangement may be briefly described as follows:

Assume thatthe razor-is being 7 the face in a forward direction, that is with the sharp edge of the blade pointed drawn across in the same opposite directionthe whisker becomes unhooked andhas an opportunityto spring up from'iun- "der tlieedge er the blade and to extend inte the notch of the cutter barso that as the blade and cutter bar simultaneously return to" the cutting position the whiskerv is inpositlon to be cut of! again, and this operation maybe repeated several times while passing over a single whisker due "to the high speed at which the blade and cutter bar are oscillated. In order to. further reduce times the razor must be passed over the face, I form thecutter bar in two parts eaclipart carrying a set of slots equally spaced, but staggered with relation toeach other so that the guards or partitions on one of the members are the cutting edges for the slots, in the other mem- "drawn sees the nee in the the number of ber this gives substantially full coverage of the face as the razor passes over it.

By the above arrangement which provides for two lines of cutting edges at the termination of the recesses of Bi and 22 it will be noted that the cutting takes place at two definite points in the oscillation of the cutter bar and blade holder. This arrangement gives the operator a better chance to get a close shave by passing the razor several times over the face, as there is more freedom of variation in the angle at which he may hold the razor with respect to the skin.

Another feature of this razor is that the surfaces of the cutter bar and blade which are straight and unbroken when the slots are covered provide a surface which may be pressed up firmly against the face and since the blade is tangent to the cylindrical surface of the cutter bar, the outside angle of junction, that is to say,

the angle at which the skin must bend in order to lie closely against the junction of the surfaces, is only reduced from 180 degrees by the angle at which the cutting edge of the blade is formed. This edge should never be more than 30 degrees and may be as thin as 5 or 10 degrees if the blade is made of steel of a sufficient quality. An angle of approximately 10 degrees is preferred. For that reason the outside angle of junction is somewhere in the order of 1'10 degrees and not more than 150 degrees at the most.

This greatly assists in bringing the line of junction of the cutting members close to the root of the hair.

The object of the. invention is to produce a generally new and improved razor of the type above indicated and the invention will be better understood from the following description and accompanying drawing referring to which:

Fig. 1 shows a side elevation of a razor built according to my invention together with a part of the handle.

Fig. 2 is a sectional elevation somewhat similar to Fig. 1, except that parts are shown in section and others broken away.

Fig. 3 is a plan view of the device shown in Figs. 1 and 2.

Fig. 4 is a sectional elevation of parts of the razor taken along the lines 3-3 of Fig. 1 looking in the direction of the arrows.

Fig. 5 is a sectional elevation of parts of the razor taken along the lines A-A of Fig.2 looking in the direction of the arrows.

Fig. 6 is a diagram showing the formation of the edge of the blade and the relation of the blade to the cutter bar.

In constructing the razor any suitable form of motor may be used and may be conveniently carried in the handle. If an electrical motor is used it may be connected to ordinary house current by means of a cord, plug and socket in the usual manner of connecting electrical appliances. As the specific construction of the motor and the source of power supply are well known in the art and have no particular importance in connection of -the present invention they are not shown.

The numeral I indicates a handle containing any suitable type of motor for driving the shaft 2, the motor is indicated in dotted lines in Fig. 2 and the operating speed is preferably in the order of 3 to 5 thousand R. P. M.

The handle which is preferably made of fiber, Bakelite, hard rubber or some other heat insulating compound, is provided with a transverse slot at one end in which is mounted the frame 3 of the razor head, this frame being detachably held in place by the thumb screw 4. The end of the shaft 2 is provided with an eccentric projection 44 which engages a corresponding eccentric recess in the cam member 5 which is also provided with another bore of different eccentricity which is fitted over the end of the shaft 2. The cam member 5 is journaled at 55 in the frame 3 and thus forms a bearing or support for the end of the shaft 2 which is loosely fitted in the bore 66 whichextends through the member 3.

The upper side of the cam member 5 is provided with an eccentric projection terminating in a ball 6. The eccentricity of this ball is in the order of 5; of an inch or slightly more whereas the eccentricity of the earn 5 is in the order of /64 of an inch so that the total throw or oscillation of the cutter bar l0 will be slightly more than of an inch and the oscillation of the edge of the blade will be less than half as much. The cams 5 and 6 are oppositely arranged so as to properly time movements of the parts which they control. This arrangement also assists in counter-balancing the arrangement for smooth operation.

The frame 3 is made up in two halves as indicated in Fig. 5 and these halves are fitted together and securely located with respect to each other by means of dowels 3 and screws 1, the heads of the screws being counter-sunk as indicated by the dotted lines of Fig. 5 so as not to interfere with the frame.

The frame is provided with a pair of stub shafts or pins 9 upon which the cutter bar It) and the blade holder II are mounted. Any suitable means may be provided for retaining the stub shafts 9 in position, but I prefer to use stub shafts sumci'ently large so that they will be held in position by the clamping action of the two halves of the frame 3 when bolted together by the bolts or screws 1. The blade holder II is provided with a cap l2 hingedly mounted thereon by means of the pins or rod l3. The blade holder is provided with a shelf 23 having surfaces to support therear part of the lower side and also the rear edge of the blade. The cap I! is provided with a blade contacting portion as indicated-at 24 which rests against the middle portion of the blade 15, the front or cutting edge of which rests on the cutter bar and the rear edge or surface which rests on the blade holder at 23. One or more compression springs H, of sufficient strength to hold the blade firmly in position without pressing it forcibly enough to cause excessive wear, are mounted between the lower edge ofthe cap and-the .blade holder and the projection IS on the blade holder. The blade holder II is normally biased in clockwise direction with respect to Figs. 1 and 2, and the projection l8 firmly held against the surface of the cam 5, by means of the spring I! which is attached to the frame by means of the screws II. The spring I! may, if desired, take forms other than that shown as it will be understood that its function is merely to hold the projection I against the surface of the cam 5.

The cutter bar is formed in two separate portions Ill and 20 which areheld together by rivets 2|. The member In is provided with a fiat surface for contactwlth the member 20 and, these surfaces are preferably ground after hardening so as to secure a perfect fit. The member III is also provided with a multiplicityof parallel slots ll separated by partitionsv 31. The member 20 bar, a-blade having a cutting edge traversing said I is also provided with a number of transverse hair receiving recesses orslots 22 separated by partitions 32. By thisarrangement it will be. seen formed. at an acute angle, as indicated Figs. 2 and 6, serve as shearing edges at. the ends of the that the end of the partitions '32"; which are slots 8| while the bottoms of the slots 22 being ting edge ground at anangle of approximately By so grinding the blade, the skin clearance is increased from that indicated by the dotted lines in Fig. 6 to that shown in solid lines. The sharpened edge is held lightly but firmly against the cylindrical surface by means of the spring H, the positioning of the blade being such that the lower surface forms a right angle with a radius drawn to the point where .the edge of the blade contacts the cutter bar. This is for the'purpose of securing minimum frictional area with maximum clearance space for the cutting edge to contact the skin.

In forming th cutter bar the best procedure is to rough machine the members In. and 20 to harden these members, then to surface grind the contacting surfaces, next to rivet the members together by means of the rivets 2| and finally to cylinder grind (lapping if necessary) the assembled cutter bar. If the inside of the holes 36 which receive the stub shafts 9 are found to be roughened during the hardening process, these holes should belapped before. the cylinder grinding is done. I

The diameter of thecutter bar should be kept as small as consistent with conveniencein machining,a diameter of to of an inch is quite satisfactory, the other parts, of course being made in proportion.

In operation the cams 5 and 6 are rotated by the motor shaft 2 and speed of 3'to 5 thousand R. P. M. imparting oscillations at a corresponding rate to the blade'holder and to the cutter.

bar. The degree of oscillation of the cutter bar, however, is at least two to three times as great asthe degree of oscillation of the blade. The-razor is operated to shave in the ordinaryrmanner except that a backward stroke of the blade with respect to the skin has been found to give a quicker shave in some instances. The blades may be conveniently changed from time to time merely by pressing on the extension 39, the lower side of the cap l2 thereby compressing the "springs recesses and cooperating with saidsides toprovide a shearing action, and means for moving both said cutter bar and said; blade, to effect a shearingfaction. ,j I i a w '2. In a dryshaver; a cutter bar'hav'inga plurality 'of hair receiving recesses formed therein, each-of said; recesses having a shearing edge at one side there-oi! and said shearing edges being in alignment and extending from end to end of'said cutter bar, 5a blade resting on the surface )of said bar's and passing over said recesses, and a shearing edges 'andmotordrive'n' meansjfor im parting an oscillating and said cutter bar. I, I 1 g Y 3. Ina dry shaver, a cutter bar formed of two members, recesses in both of said members having sidesforming shearing faces, said recesses motion to both said blade being staggered with relation to eachpthenan'd a cutting blade traversing said recesses and cooperating withsaid shearing faces. g t

4. In a dry shaver,a-recessed rapidly oscillatable cutter bar including a plurality of shearing laces, a-srelatively slowly shiftable blade holder, a blade having its cutting edge resting on said cutter bar and its rearfedge supported by said blade holder, and a cap for said blade holder, said cap having means for contacting said blade at'a point between the portions which'are supported by the cutter barand the blade holder.

5. A cutter bar for dry shavers comprising a pair of members secured in fixed relation and contacting each other along a finished surface, at least one of said members being recessed, the finished surface on the other member forming a wall for said recesses. Y

6. In adry shaver, a cutter bar formed of two members, one of said members being recessed and the other formingjshearing walls at the ends of said recesseaablade member, and means for moving the shearing walls with respect to said blade-to provide ashiearingoperation.

7. In a dry shaver, a frame, a cutter bar piv- V otally mounted in said frame, a blade holder concentrically pivotally mounted on an axis coincident with the pivotal axis of" thecutter bar,

7 a power driven rotary shaft supported in said frame, and drive means between said shaft and said cutter bar and blade holder whereby the latter is caused to be oscillated by an amplitude I less than the amplitude of oscillation of said cutcutter bar comprising a support to the other edge, a cap for said blade holder, said cap hav- H and releasing the blade. The cutter bar may 7 ing means for contacting the central portion of the blade and holding in contact with said outter bar and said blade holder, displaceablespring means for holding said cap in position, said cap being displaceable to release the pressure of the blade against the cutter bar and permitting ready projection at the end of said drive shaft for actuating said cutter bar, and a cam on said drive shaft for actuating said blade holder.

10. In a dry shaver, a frame, a cutter bar pivotally mounted in said trame, a pivoted blade holder carried by said frame, a blade carrier in said blade' holder, yieldable means for holding said blade in contact with said cutter bar, and means for oscillating said cutter barand blade holder including a power driven element and cams on said power driven element, said cams being so constructed and arranged as to oscillate said cutter bar and blade holder simultaneously .in opposite directions, whereby the action 01' the parts will be counterbalanced.

11. In a dry shaver, a pivotally mounted oscillating cutter bar formed of two members, one of said members being recessed and the other forming shearing walls at the end or said recesses, a blade cooperating with said walls to effect a shearing operation, said blade having a continuous rectilinear cutting edge extending from end to end oisaid bar, an oscillating holder for said blade mounted on pivots coincident-with the pivotal axis ot said bar, and means for oscillating said bar and blade holder.

12. In a dry shaver, a pivotally mounted oscillating cutter bar formed oi two members, one of said members being recessed and the other forming shearing walls at the end of ,said recesses, a blade cooperating with said walls to effect a shearing operation, said blade having a continuous rectilinear cutting edge extending from end to end of'said bar, an oscillating holder for said blade mounted on pivots coincident with the pivotal axis of said bar, and means for oscillating said bar and blade holder including a rotating shaft, and oppositely arranged cams.

GEORGE R. meson. JOHN mam. 

